Continuous diffusion battery and treatment



April 26, 1949.

Filed Sept.

CONT INUOUS H. F. SILVER DIFFUSION BATTERY AND TREATMENT 4 Sheets-Sheet 1 HAROLD E SILVER IN VEN TOR.

' ATTORNEY April 26, 1949. H. F. SILVER 2,468,720

CONTINUOUS DIFFUSION BATTERY AND TREATMENT Filed Sept. 28, 1945 4'SheetsSheet 2 HAROLD E SHMEH ZNVENTOR iiraiw ATTORNEY April 26, 1949. $|LvER v 2,468,720

CONTINUOUS DIFFUSION BATTERY AND TREATMENT Filed Sept. 28/1945 T 4 She ets-Sheet 5 HAROLD E SILVER I N V EN TOR.

ATTORNEY April 26, 1949. H. F. SILVER 2,468,720

CONTINUOUS DIFFUSION BATTERY AND TREATMENT Filed Sept. 28, 1945 4 Sheets-Sheet 4 HAROLD F. SILVER INVENTOR.

BY d/z zezm A TTORNEY Patented Apr. 26, 1949 UNITED STATES I PATENT, OFFICE CONTINUOUS DIFFUSION BATTERY AND TREATMENT Harold F. Silver, Denver, 0010. Application September 28, 1945, Serial No. 619,163

13 Claims. (01. 127-45) This invention relates to a method of and apparatus for the treatment of divided solids material with liquid, and more particularly to a continuous diffusion method and apparatus useful in the processing of sugar beets, sugar cane, corn, other grain products, and the like. The present application is a continuation-in-part of my co-pending application Ser. No. 454,098, filed August 8, 1942, for Continuous diffusion process,

now Patent No. 2,390,131. The apparatus of the present invention is particularly adapted to carry out the continuous diffusion process disclosed and claimed in my said co-pending application, and the method and apparatus of the present invention include improvements upon the process disclosed and claimed and the apparatus disclosed in my said co-pending application.

Prior to the development of the process of said co-pending application, no satisfactory continuous diffusion process was available which satisfied the requirements of the industry sufficiently to come into general use, so that the batch method of treatment had been used almost exclusively. However, the batch method usually requires a large amount of heavy manual labor, with consequent high labor costs, and is relatively inflexible in accommodating operational variations, but, an inherent reliability--coupled with the lack of a satisfactory continuous process -resulted in its continued usage.

The diffusion process disclosed and claimed in my said co-pending application includes the steps of moving divided material, such as beet cossettes, through a confined treatment zone having a succession of treatment stages, each such stage including alternate downward and upward courses of cossette travel, feeding cossettes into one end of the confined zone, flowing liquid, such as juice, in a progressive movement through the succession of treatment stages in a separate course generally countercurrent to the cossette travel, moving the juice into the respective treatment stages at a point intermediate the ends of the downward course, directing the juice so intermixed with cossettes through a substantial extent of the treatment -sta'ge concurrent with the travel of the cossettes, withdrawing juice from the succeeding upward course at a point near the top thereof to permit draining of the cossettes before they are again brought in contact with the juice at the intermediate position in the downward course of the next treatment stage, and discharging the juice and cossettes separately from the treatment, as at the ends of the countercurrent courses.

Other desirable features, some of which are alternative, include moving the cossettes at a substantially uniform rate, moving the cossettes and juice at different rates, moving the juice at a slower or faster rate than the cossettes, varying the rate of cossette travel during different cycles, and moving the juice through each treatment stage under the impelling action of the cossettes. Preferably, the treatment stages are spaced at uniform intervals, and the treatment zones are closed from the atmosphere. If desired, inert gases are directed to a portion of each upward course above the point of liquid withdrawal.

The foregoing continuous diffusion process satisfies numerous requirements necessary for satisfactory operation, such as a high rate of diffusion, provided by maximum cossette or slice area; relatively continuous contact of cossette or slice area with juice or solution; proper density cossette fill and alteration of density to suit'beet conditions; countercurrent flow of cossettes and juice; avoidance of mutilation of cossettes; ability to vary and control the temperature in any part of the circuit properly; low draft and low heat consumption; high density and purity of the raw juice, commensurate with the beets handled; uniform and maximum exhaustion of cossettes; uniform and minimum sugar loss in pulp; and a minimum of operating labor. In addition, by such process, a relatively large volume of cossettes may be treated in a zone of relatively small superficialarea; a relatively high extraction may be obtained; little oxidizing action, or other deleterious chemical reaction. tends to occur; selective variation of the respective movements of liquids and solids is obtained; and a close control of the liquid-solids contact intervals at one or more stages of the treatment is also obtained.

Among the objects of the present invention are to provide apparatus particularly useful in carrying out the process of my said copending application Ser. No. 454,098 now Patent No. 2,390,131; to provide such apparatus which provides a uniform cossette or slice fill; to provide such apparatus which requires a minimum of mechanical power, and also a minimum of attention; to provide such apparatus which is continuous in 0peration; to provide such apparatus which instages, and which substantially automatically pre vents an overload of the apparatus; to provide apparatus in which a periodic separation of liquid and divided solids material is effected rement; to provide one -formof such apparatus which includes a continuous conveyor for moving divided material through a sinuous conduit providinga plurality of stages, each stage having a pair of substantiallyvertical portions connected at the lower ends thereof; to provide an efficient and effective drive for such conveyor; and to provide such a drive by which the total load is substantially equally distributed.

Among further objects of this invention are to provide an additional embodiment comprising apparatus which does not require the use of a continuous conveyor; to provide such apparatus in which an adequate hydraulic head is maintained by a circulating impeller; and to provide diffusion apparatus which is adaptable not only to the treatmentof sugar beets or cossettes produced therefrom, but also to the treatment of other materials, including sugar cane, grain such as corn, and other solids in divided or finely divided form, wherein a solid and liquid contact treatment is to be carried out.

Among additional objects of this invention are to provide improvements upon the process disclosed and claimed in my said co-pending application ser. No. 454,098; to provide such process improvements by which foam and evolved gases are adequately removed; to provide such process improvements by which materials other than sugar beet cossettes may be treated; to provide such process improvements through which a loose granular material may be treated. such loose granular material being of such character that when suspended in. liquid it cannot be effectively carried along by a conveyor mechanism; and to provide such process improvements by which-variations in dimensions in various portions of the treatment stages tend to enhance the operation. An additional object of this invention is to provide apparatus particularly adapted to carry out the above process improvements in an effective and efficient manner.

Other objects of this invention, and the novel features thereof, will become apparent from the following description, taken with reference to the accompanying drawings in which:

Fig. 1 is a side elevation of diffusion apparatus comprising one embodiment of this invention;

F Fig. 2 is a top plan view of the apparatus of Fig. 3 is an end elevation of the apparatus of Fig. 1;

Fig. 4 is a vertical section taken through a feed device forming a portion of the apparatus, shown in Figs. 1 and 3;

Fig. 5 is a, partially diagrammatic cross section of one stage, cell or section of the apparatus of Fig. l, the view loole ng toward the apparatus from a direction opposite to that in which Fig. 1 views: it; Fig. 6 is an enlarged plan view of a rotating drainage device, forming a portion of the apparatus of Fig. 1;

Fig. 7 is a longitudinal sectional view restricted to one end of the spider assembly comprising a portion of the drainage device of Fig. 6;

opposite end of the spider assembly forming a portion of the drainage device of Fig. 6;

Fig. 10 is a vertical section taken along line- Ill-l0 of the drainage device of Fig. 6, and also showing an associated cleaning device;

Fig. 11 is a restricted longitudinal section taken along line ll-ll of Fig. 10;

Fig. 12 is a cross section showing a conveyor and associated parts adapted to remove divided material from the final drainage device;

Fig. 13 is an enlarged top plan view, partially broken away to show the interior construction around the drainage device;

Fig. 14 is a vertical section taken along line 14-14 of Fig. 13, and particularly illustratinga vent arrangement for removing foam, evolved gases, and the like, from the liquid or juice; and

Fig. 15 is a cross section taken along line l5-I 5 of Fig. 14.

As illustrated in Figs. 1 to 3, inclusive, apparatus constructed in accordance with this invention may comprise a-battery B, particularly adapted to carry out the continuous diffusion process of application Serial No. 454,098, and also process improvements described herein. The battery preferably consists of a plurality of cells, interconnected to provide a continuous treatment zone, and designated as C1 to C19, inclusive, in accordance with the movement of divided solids, such as beet cossettes, therethrough. The cells are disposed in a vertical position, preferably in two tiers to conserve floor space, to permit gravity flow of juice from the upper to the lower tier, and to reduce the amount of power required to drive a continuous conveyor, which extends through the cells and is adapted to move the divided solids therethrough. Also, a two tier arrangement reduces to a minimum the non-working portion of the conveyor, i. e., that portion between the discharge of treated cossettes and the entrance of untreated cossettes.

The battery B is provided with an inlet 1, incorporating a novel feeding device which will be described in detail hereinafter, for feeding the cossettes into a vertical inlet portion 20 of the closed continuous conduit formed by the cells. Each cell comprises a section of the conduit and includes a substantially vertical portion providing a downward course 2| and a substantially vertical portion providing an upward course 22, the vertical portions being connected together at the bottom by a semi-circular conduit portion 23. Each cell is connected to the adjacent cell by a similar but inverted semi-circular conduit portion 24, which connects the upward course 22 of one cell with the downward course 2| of the next cell. The inlet 20 extends to the downward course 2| of the first cell Cl, while a riser 25 connects the upward course 22 of cell C11 (the last cell in the lower tier) with a conduit portion 24 which is connected with the downward course 2| of cell 012 (the first cell in the upper tier). The exhausted cossettes are discharged from cell C19 (the last cell in the upper tier) into a hopper H, provided with a discharge pipe or outlet 26 and associated scroll conveyor 21 through which discharges the'exhausted cossettes. It will be understood, of course, that any number of cells may be used, as desired, depending principally upon the required capacity, the optimum rate of movement of the conveyor, and the time required in each cell for the extraction of sugar therein. Thus, a nineteen cell battery is shown chiefly for convenience in illustrating the operating principles. Also, the number and proportion of cells in the upper and lower tiers may be varied, since the presence of eleven cells in the lower tier and eight in the upper is merely the result of the space occupied by hopper H in the upper tier. Thus, the number of cells in the lower tier will usually exceed the number in the upper tier in accordance with the amount of space occupied by hopper H.

The cossettes are moved progressively from inlet 20. through the lower tier of cells, up through riser 25, and then through the upper tier of cells to the hopper H, as indicated by the solid arrows of Fig. l. Simultaneously, the liquid, such as water for extraction of sugar from sugar beet cossettes, is passed generally countercurrent to the movement of cossettes, but in each cell the liquid passes along with and in the same direction as the cossettes, The juice passes from cell to cell' through launders L, as indicated by dotted arrows in Fig. 1, the launders being mounted along the upper portion of the cells on either side thereof.

Fresh water is continuously introduced through an inlet pipe 28 and a passage formed in launder L leading generally alongthe dotted arrow to the downward course 2i of cell C19 (the last cell in the upper tier), through which almost exhausted cossettes pass in the direction of the solid arrow. This water enters cell C19 at a point intermediate the upper and lower ends of the downward course 2i, and passes with the cossettes downwardly through the downward course 2 I, then around the lower conduit portion '23, and upwardly through the upward course 22, being separated from the cossettes by suitable means, such as a rotating screening or drainage device S, mounted at a point adjacent the upper end of the upward course 22 of each cell.

From the rotating screen device S, the water or juice, now carrying such sugar as could be extracted from almost exhausted cossettes, passes into the launders L, in which it flows by gravity to the downward course 2! of the adjacent cell Cw, as indicated by the dotted arrow. The juice similarly fiows by gravity from cell to cell countercurrent to the cossettes, and passes through each cell with the cossettes, until discharged from cell C12. From the screen device S of cell C12, the juice flows through pipes 29 to an upper manifold 20, thence through a vertical pipe 3| to a lower manifold 32, from which the juice flows through pipes 33 to the lower launders L, and in the lower launders to the downward course 2| of cell Cu, as indicated by the dotted arrow of Fig. l. The juice flows from cell to cell of the lower tier, in the same manner as it-flows along the upper tier, until it reaches cell C1. It will be observed that each launder or liquid conduit L has its outlet adjacent the divided material inlet end of a cell, while the intake of each conduit is adjacent the divided material discharge end of a preceding cell, with respect to the direction of movement of the cossettes by the conveyor, As is clear from my said patent and the present specification, a preceding cell is one toward which the conveyor is moving divided material.

From cell C1, the juice, having progressively increased in sugar concentration and having by then attained such a high sugar content that it is usually unsuited for additional extraction, flows from the screen device S, as indicated by the dotted arrow, to a rotating screen device S, which is adapted to remove relatively fine divided particles, which may have been carried along with the juice. From screen device S, the juice is discharged throughan outlet :4 from whence it may be piped to a point of further treatment.

As illustrated in Fig. 5, the movement of the cassettes through each cell maintains a leaving liquid level 38 in the upward course 22 at a higher elevation than an entering liquid level 3] in the downward course 2|. The upward and downward courses of the cells are preferably rectangular in shape, and the conveycr'for moving the cossettes through the battery is preferably correspondingly constructed, such as including a plurality of equally spaced rectangular flights 38, each comprising a laterally extending, perforated channel, or the like. The flights are attached at the mid-portions of their ends, as by welding, to spaced links of a pair of laterally spaced, endless chains 39. In the semi-circular conduit sections 23 and 24, the chains engage sprockets or idlers 40 which are mounted on shafts 4| and maintain the flights in position during movement through the conduit. In addition, all or only a portion of the shafts may be driven to drive the conveyor. Such shafts are preferably selected so that the load on each is substantially the same Also, the driving shafts are preferably at the top of a cell, rather than at the bottom, since gravity tends to cause the conveyor to move downwardly in the downward course, but resists movement of the conveyor through the upward course.

For the above purpose, and as shown more clearly in Fig. 1, a plurality of motors 42 are mounted on platforms 33, disposed in accordance with the shafts to be driven. Each motor is provided with reduction gearing 5d, connected with the respective shaft, and also adapted to drive, as by chains 45, sprockets 46 of the corresponding rotating screen devices S. The remaining screen devices may be driven by auxiliary chains 47, connecting sprockets 48, so as to rotate each screen.

The motors may be disposed as shown, i. e., at the top of the upward courses of cells C4, C1, C10, C13, C16, and C19 and at the upper end of riser 25. Generally, along both the upper and lower tiers, the driving motors are placed approximately three cells apart. There is a driving motor just prior to cell C11, the last cell in the lower tier, and a driving motor is also preferably installed at the upper end of riser 25, because of the weight of the conveyor and cossettes to be moved upwardly through the riser. The motors are adjustable speed motors having a substantially constant speed characteristic for any particular adjustment. It is necessary to provide a uniform speed of movement of all portions of the conveyor, and to adjust the speed of all the motors simultaneously in changing the rate of movement of the conveyor from any higher speed to lower speed, or vice versa,

The conveyor moves continuously through the apparatus, from cell Ci to cell C19, then along the upper end of hopper H, with the flights in vertical position to cause the cossettes to drop out, and thence over idlers mounted on shafts 50 and 5|, and into inlet portion 20. The battery B may be mounted upon a foundation 52.

The feed inlet device I, which tends to maintain the load and feed substantially constant, may be constructed as illustrated in Fig. 4. The device I is installed within a substantially rectangular housing 54, and includes an auxiliary conveyor comprising two endless link chains 55 movable in a loop movement around sprockets- 56 mounted on shafts 51. A plurality of flights" around through a'semicircular housing section 60 to a discharge section above inlet conduit portion 20. Edge 6| of the discharge section may be slanted sidewise to provide an opening of triangular shape for more even feeding of cossettes through inlet portion 20. In case the inlet portion is full, the cossettes will not discharge into the same, but will merely be carried around by the auxiliary conveyor through a semicircular housing section 62, at the opposite end of the auxiliary conveyor, and then around the back side of the conveyor. Thus, as long as the inlet portion 20 remains full, the cossettes will merely be carried around and around the auxiliary conveyor, and no additional cossettes will be picked up from the free duct 59 by the auxiliary conveyor. However, as soon as the cossette level in inlet portion 20 drops, additional cossettes will fall therein, and additional cossettes will be picked up by the auxiliary conveyor and delivered to the main conveyor.

One shaft of the auxiliary conveyor is driven by a motor 83 mounted on a platform 64, and preferably includes an integral speed reducer.

The rotating screen or drainage devices S may be constructed in any suitable manner, as by screening or perforated material in cylindrical form mounted on a suitable supporting structure. Due to the possibility of woven wire cloth or screening becoming clogged by small particles, and because of other advantages, a preferred construction is that illustrated in Figs. 6 to 11, inclusive. Preferably, the central portion of the screen device is immersed in the pulp or mixture of juice andcossettes at a point near the top of the upward course of each cell, as in a compartment connecting with the upward course at the desired point, such as compartment 69 of Fig. 5. Liquid tends to flow into the compartment as divided solids are moved upwardly into portions 24. Also, as the cossettes are moved upwardly, the juice drains therefrom, so that separation of the cossettes and juice is obtained.

The ends of the screen devices extend into the launders L, and in the construction illustrated in Figs. 6 to 11, inclusive, the central portion of the screen device S includes a plurality of rings 10, having circumferential slots II and longitudinally extending ribs 12 spaced about the r inner periphery thereof. The four ribs I2, one of which is provided with a keyway I3 as in Fig. 10, engage the four ribs of a supporting spider I4. The ribs of the spider are provided with alternate holes 11 adjacent the center thereof, to provide free circulation of liquid along the spider during rotation. During use, the liquid flows through the slots II and along the spider to the ends of the screen, at which points the liquid is discharged into a discharge compartment of' the launders L, to flow to the next cell. The slotted rings 10 are flanked on either side by imperforate rings 18 adapted to cooperate with a suitable hole in the wall of the discharge compartment of the launder.

'Ihe ribs of the spider may be welded or otherwise suitably secured to flanges l9, at'either end thereof. At one end, a drive shaft 80 is attached to the flange, sprockets 40 and 48 -being attached thereto. Suitable bearings are provided for the drive and stub shafts, such bearings being mounted in or attached to the launders L.

To maintain the slots of the rings 10 free from cossettes or divided solids material, which would otherwise tend to clog the same, a cleaning device may be provided which, as in Figs. 10- and 11,

4 lodged to assure relatively free flow of liquid into the interior of the rings I0.

A cleaning device D, which may be constructed as illustrated in Fig. 12, is provided to remove the material screened out of the final juice by screen device S and to return the screened solids to the downward course 2| of cell C1. The device D includes an auxiliary conveyor consisting of a plurality of endless link chains 81 carrying horizontal rods 88 attached to the chains which engage sprockets 89, which are mounted on rings 10. Preferably, rods 88 comprise pipes or round bars to which are welded rectangular scraper bars 80, Or the like, adapted to move divided solids from around the rings 10. With the screen device S' rotating in the direction of the arrow of Fig. 12, rods 88 carry such material upwardly along a curved plate SI; and then into a discharge space 92. As the rods 88 pass beneath a directionreversing plate 93, the solids drop into discharge space 92. The rods 88 then pass upwardly and over a return plate 04, and thence beneath the screen device to continue the cleaning operation.

During passage along curved plate 9! and return plate 90, rods 88 are maintained in position by end guiding bars and 86, respectively, attached to plates 9! and 94. Direction-reversing plate 03 may be mounted for vertical adjustment in any suitable manner, as by being attached to a support 91, each support being positioned vertically by an adjusting rod 98. The discharge space 92 connects with the inlet or downward course H of cell Cl.

In further accordance with this invention, the launders L, through which the juice is transferred from cell to cell countercurrent to the movement of the cossettes from cell to cell, may be constructed as illustrated in Figs. 13 to 15, inclusive. Upon separation from the intermixture of juice and cossettes by drainage or screen device S, as indicated previously, the juice flows toward both ends of the screening device, into end compartments I00 of the launders L. Each end compartment is formed between a vertical interior wall IN and a vertical exterior wall I02, these walls extending longitudinally of the apparatus. Also, each compartment is separated from the adjacent end compartment by an end wall I03, which extends transversely and upwardly to a point near a top plate I04, thereby forming a vent I05. Suitable openings 83 may be provided in wall I04 to permit the fiow of foam and evolved gases out of the cells into vent I05. Vents I05 permit the passage of foam and evolved gases from stage to stage, thus preventing any alteration of the liquid level through undue pressure created in any compartment clue to such foam or evolved gases. As will be evident, the foam and evolved gases flow through vents I05, from compartment to compartment in each tier, until the last compartment is reached, from which the gases may be vented to the atmosphere in any suitable manner.

The bottom plates I 06 of each compartment extend to a point spaced from the end wall opposite the screening device S, as in Fig. 14, and

the juice removed through the screening device.

flows through the aperture I01 so formed into an inner compartment I08 of the next stage of the apparatus to which juice is delivered. As in Fig. 5, the inner compartment I08 is preferably provided with louvres I09 or other suitable openings to permit the juice to flow into the moving body of cossettes, without any tendency for the cossettes to enter the inner compartment.

For handling more finely divided material, such as corn or other cereal grains, treated for extraction of certain constituents therefrom, and particularly material which cannot be effectively moved upwardly by a continuous conveyor of the type utilized in the apparatus of Fig. 1 et seq., a slightly different method may be utilized. In such method, the liquid is moved generally countercurrently to the divided solids, and in each stage the liquids and solids are intermixed and move in the same direction, as in the previous method, but the divided material is moved through the stages by an impelling force applied adjacent the lower end of the downward course of each stage, such impelling force thereby being applied to the intermixture of divided solids and liquid.

It will be understood, of course, that in the first embodiment any desired number of cells may be utilized in either tier, and also that all cells may be disposed in a single tier, or at positions in vertically stepped arrangement, or in' any other arrangement desired, although two tiers, one above the other, is the preferred arrangement in this embodiment for the reasons previously indicated. It will further be understood that the cells of either embodiment may be disposed vertically, or in stepped arrangement, one above the other, and that the liquid may be pumped from cell to cell, although a gravity flow from cell to cell is preferred, for economy and simplicity. Fig. 1 shows the stepped arrangement of both cells and launders, so arranged that flow of juice between inlet 28 and outlet 34 is provided.

From the foregoing, it will be apparent that the method and apparatus of this invention attains the objects hereinbefore specified, and further that the method and apparatus of this invention permit a wide variety of materials to be treated. Although two embodiments of this invention and certain variations thereof have been described, it will be understood that the method of this invention, and also the method disclosed and claimed in my co-pending application Ser. No. 454,098, may be carried out in other apparatus. It will also be understood that other embodiments of the apparatus of this invention may exist, and various other changes may be made, both in the method and apparatus, without departing from the spirit and scope of this invention.

Where the term sinuous" is used in the specification it is intended to define a winding course of travel in the same sense as the definition given in Websters New International Dictionary, 2nd ed., namely: Bending in and out; of a serpentine or wavy form; moving with bends; winding.

What is claimed is: a

1. Apparatus for treating divided solids material with a liquid, comprising a sinuous closed conduit substantially rectangular in shape, said conduit having a plurality of sections disposed in two substantially horizontal tiers one above the other, each section including a downward and upward course connected at the bottom by a substantially semi-circular conduit portion, with similar semi-circular conduit portions connecting the upper end of the upward course of each sec- 10 tion with the upper end of the downward course of the next section, said conduit having a vertical inlet portion extending from one end of the upper tier downwardly to the downward course of the first section of the lower tier; a riser connecting the last cell of the lower tier with the first cell of the upper tier; a hopper for receiving discharged divided solids from the last cell of the upper tier; an endless conveyor including laterally spaced chains having attached thereto longitudinally spaced perforated flights, said conveyor moving said divided solids from said inlet portion to the downward course of the first cell in the lower tier, then successively through the downward and upward courses of each cell of the lower tier, then up through saidriser to the upper tier,then successively through the downward and upward courses of the upper tier, then passing along the upper portion of said hopper to discharge the treated solids into said hopper, and then passing into said inlet portion; rotatable shafts mounted in each semi-circular conduit section; members for guiding and driving said conveyor and mounted on said shafts within. said conduit so as to be engaged by said chains; drive means for spaced shafts, each driven shaft being located in an upper semi-circular conduit section, and the driven shafts being spaced so that the load on each driven shaft is substantially the same during normal operation; means for supplying fresh liquid to the downward course of the last cell in said upper tier; means for removing liquid from the upward course of the first cell in the lower tier; a liquid outlet compartment disposed between the downward and upward course of each cell and connecting with the upward course of said cell at a point near the top thereof; a drainage device extending into the outlet compartment of each cell for removing liquid and conveying the same outwardly to each side of said cell; a liquid inlet compartment connecting with the downward course of each cell; and at least one launder disposed along a side of the upper portion of the upper and lower tiers of cells, each launder including a plurality of upper compartments for receiving liquid from said drainage devices and an equal number of lower I compartments, each lower compartment connectmg with a discharge compartment and with the liquid inlet compartment of the next adjacent cell, said launders being constructed and arranged to convey the liquid generally countercurrent to the movement of solids, but to permit the movement of liquid along with the solids through each cell.

2. Diffusion apparatus, comprising a series of treatment cells interconnected for the progressive movement of divided material therethrough, a feed inlet for divided material at one end of said apparatus, conveyor means in each said cell for imparting said progressive movement to divided material, a plurality of conduit members arranged with each member extending between two cells of the series to impart a gravity flow of liquid in a direction generally countercurrent to the travel of divided material through the apparatus, the outlet of each conduit member being positioned adjacent the divided material inlet end of each cell and the intake of each said conduit member being adjacent the divided material discharge end of a preceding cell, whereby the liquid is caused to flow concurrently with the divided material throughout substantially the entire length of each cell, said conveyor means including apertured members and a portion of said means extending above th level of liquid adjacent the discharge end of each cell to elevate divided material out of the liquid and drain the material before it is again brought in contact with the liquid at the point of intermixture in the next treatment stage, a screening member disposed in the liquid adjacent the portion of said conveyor means which elevates divided material above the liquid level, said screening member being adapted to screen the liquid before it passes into the conduit intake, a liquid inlet at the end of apparatus opposite from that at which said feed inlet for divided material is positioned, and discharge outlets" for the liquid and the divided material at the ends of the apparatus opposite their respective inlets.

3. Diifusion apparatus comprising a series of treatment cells disposed at progressively higher elevation and interconnected for the progressive movement of divided material therethrough, a feed inlet for divided material at one end of said apparatus, conveyor means in each cell for imparting said progressive movement to the divided material, a plurality of conduit members arranged with each member extending between two cells of the series and disposed in a plane inclining from one end of the series to another end thereof to impart the gravity flow of liquid in a direction generally counter-current to the travel of divided material, the outlet of each conduit member being positioned adjacent the divided material inlet end of each cell, and the intake of each said conduit member being adjacent the divided material discharge end of a preceding cell, whereby the liquid is caused to flow concurrently with the divided material throughout substantially the entire length of each cell, said conveyer means including apertured members and a portion of said means extending above the level of liquid adjacent the discharge end of each cell to elevate divided material out of the liquid and drain the material before it is again brought into contact with the liquid at the point of intermixture in the next treatment stage, a screening member disposed in the liquid adjacent the portion of said conveyer means which elevates divided material above the liquid level, said screening member being adapted to screen the liquid before it passes into the conduit intake, a liquid inlet at the end of the apparatus opposite from that at which said feed inlet for divided material is positioned, and discharge outlets for the liquid and the divided material at the ends of the apparatus opposite their respective inlets.

4. Diffusion apparatus comprising a series of treatment cells interconnected at their ends for the progressive movement of divided material therethrough along a sinuous course of travel, a feed inlet for divided material at one end of said apparatus, conveyer means in each said cell for imparting said progressive movement to the di-. vided material, a plurality of conduit members arranged with each member extending between two cells of the series to impart a gravity flow of liquid in a direction generally counter current to the travel of divided. material through the apparatus, the outlet of each conduit member being positioned adjacent the divided material inlet end of each cell and the intake of each said conduit member being adjacent the divided material discharge end of a preceding cell, whereby the liquid is caused to flow concurrently with the divided material throughout substantially the entire length of each cell, said conveyer means including apertured members and a portion of said means extending above the liquid level adjacent the discharge end of each cell to elevate the divided material out of the liquid and drain the material, at least a part of said elevating portion being mounted for movement to transfer the divided material from the drainage area of one cell to the point of intermixture in the next cell of the series, a screening member disposed in the liquid adjacent the portion of said conveyer means in different directions with adjoining cells of.

each series interconnected for the progressive movement of divided material. therethrough, a

feed inlet for divided material at one end of a first series and a liquid inlet at the adjacent end of the second series, conveyer means in each said cell for imparting said progressive movement to the divided material, a plurality of conduit members arranged with each member extending between two cells of each series and disposed in a plane inclining from one end of the series to another end thereof to impart a gravity flow of liquid in a direction generally counter-current to the travel of divided material through the apparatus, the outlet of each conduit member being positioned adjacent the divided material inlet end of each cell and the intake of each said conduit member being adjacent the divided material discharge end of a preceding cell, whereby theliquid is caused to flow concurrently with the divided material throughout substantially the entire length of each cell, said conveyer means including apertured members and a portion of said means extending above the level of liquid adjacent the discharge end of each cell to elevate divided material out of the liquid and drain the material before it is again brought into contact with the liquid at the point of intermixture in the next treatment stage, a screening member disposed in the liquid adjacent the portion of said conveyer means which elevates divided material above the liquid level, said screening mem- I her being adapted to screen the liquid before it passes into the conduit intake, a material conveyor associated with one portion of the conveyor means for transferring divided material from the forward series to the rearward series, and discharge outlets for the liquid and the divided material at the ends of the respective series opposite their respective inlets.

6. Diifusion apparatus comprising a series of treatment cells interconnected for the progressive movement of divided material therethrough, a feed inlet for divided material at one end of said apparatus, conveyor means in each said cell for imparting said progressive movement to divided material, a plurality of conduit members arranged with each member extending between two cells of the series to impart a gravity flow of liquid in a direction generally counter-current to the travel of divided material through the apparatus, the outlet of each conduit member being positioned adjacent the inlet end of each cell and the intake of each said member being adjacent the discharge end of the other cell, whereby the liquid is caused to flow concurrently with the divided material throughout substantially the entire length of each cell, said conveyor means including apertured members and a port on of said means extending above the level of liquid adjacent the discharge end of each cell to elevate divided material out of the liquid and drain the material before it is again brought in contact with the liquid at the point of intermixture in the next treatment stage, a screening member disposed at a side of the course of material travel through the cell adjacent the portion oi said conveyor means which elevates divided material above the liquid level, said screening mem-' her being submerged sufllciently to screen the liquid before it passes into the conduit intake. a liquid inlet at an end of the series of cells opposite the feed inlet, and discharge outlets for liquid and the divided material at the ends of the series opposite their respective inlets.

'7. A diffusion process, which comprises the movement of divided material through a confined treatment zone having a succession of treatment stages, feeding divided material into one end of said confined zone, flowing liquid by gravity in a, progressive movement through the succession of treatment stages along a course generally countercurrent to the divided material travel, introducing the liquid into the respective treatment stages near one end of each stage and in the path of divided material moving into said stage, directing the divided material so intermixed with liquid through substantially the entire treatment stage in an action in which the liquid moves concurrently with the travel of divided material, elevating the divided material out of the liquid at the opposite end of said stage in below the liquid level before the liquid passes.

from said treatment stage to the next'stage along its counter course, and discharging the liquid and I divided material separately from the treatment zone.

11. A process as defined in claim 7 in which the liquid moves at a diilerent rate than the divided material along the course of concurrent movement of said materials.

12. In diffusion apparatus, including a series of treatment cells interconnected for the progressive movement of divided material therethrough, a feed inlet for divided material at one end of said apparatus, conveyor meansin each said cell for imparting progressive movement to the divided material, a series of conduit members extending between adjoining cells of the series to impart a gravity flow of liquid in a direction generally countercurrent to the travel of divided an action in which the elevating movement is utilized to transfer the divided material from said stage to the next treatment stage while draining liquid back through the divided material during such elevation and before it is again brought in contact with the liquid at the point of intermixture in the next treatment stage, then subjecting said liquid to a screening action at a point adjacent to but below the liquid level before the liquid passes from said treatment stage to the next stage along its countercurrent course, and discharging the liquid and divided material separately from the treatment zone.

8. A process as defined in claim 7 in which the liquid level of a given cell is higher at its discharge end than at its inlet end.

9. The process as defined in claim 7 in which the major portion of the liquid introduced into one treatment stage from another treatment stage enters said stage at a point below the liquid level therein.

10. A difiusion process I which comprises the movement of divided material through a confined treatment zone having a succession of treatment stages, feeding divided material into one end of said confined zone, flowing liquid by gravity in a progressive movement through the succession of treatment stages along a course generally counter-current to the divided material travel, introducing the liquid into the respective treatment stages near one end of each stage and in the path of divided material moving into said stage, directing the material so intermixed with liquid through substantially the entire treatment stage in an action in which the liquid moves concurrently with the travel of divided material, elevating the divided material out of the liquid at the opposite end of said stage in an action in material, the outlet of each conduit member be-- ing positioned adjacent the inlet end of each cell and the intake of each said member being adjacent the discharge end of the other cell, whereby the liquid is caused to flow concurrently with the divided material throughout substantially the entire length of each cell, partitioning means dividing each conduit into a plurality of adjoining upper and lower compartments and arranged to provide a passage connecting an upper compartment with an adjacent but spaced lower compartment, and a screening member disposed in each cell for delivering liquid into each upper compartment.

13. In diflusion apparatus, including a series of treatment cells interconnected for the progressive movement of divided material therethrough, a feed inlet for divided material at one end of said apparatus, conveyor means in each said cell for imparting progressive movement to the divided material, a series of conduit members extending between adjoining cells of the series to impart a gravity flow of liquid in a direction generally countercurrent to the travel of divided material, the outlet of each conduit member being positioned adjacent the inlet end of each cell and the intake of each said member being adjacent the discharge end of the other cell, whereby the liquid is caused to flow concurrently with the divided material throughout substantially the entire length of each cell, a partition in each said conduit dividing its interior into upper and lower compartments and regulating the level of liquid in the conduit, anda passage extending through a succession of upper compartments above the liquid level therein to provide a wet sump vent for said apparatus.

HAROLD F. SILVER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 755,546 Rak Mar. 22, 1904 (Othelreferences on following page) Number Number Number Name Date Jellinghaus June 5, 1934 Holbeck Oct. 16, 1934 FOREIGN PATENTS Country Date Great Britain 1901 Austria Jan. 10, 1940 Germany Mar. 3, 1931 

